1. Field of the Invention
The present invention relates to an electrical connector and a vehicle airbag apparatus having an electrical connector.
2. Background Art
Electrical connectors, and in particular, plug-type electrical connectors, can provide a fast and convenient way to connect and disconnect electrically operated devices. In the case of a plug-type connector, it may be necessary for the two portions of the plug—e.g., the male and female portions—to be fully seated to ensure an adequate electrical connection. One way to help ensure that two portions of an electrical connector are fully seated with each other, is through the use of a connector position assurance device (CPA).
A CPA can be configured such that it cooperates with the electrical connector to provide a visual assurance that the connector is fully seated. For example, a CPA may have seated and unseated positions which are readily discernible by visual inspection. The CPA can be configured such that it cannot be moved from the unseated to the seated position unless the two portions of the connector are fully seated with each other. Moreover, a CPA can be configured so that the two portions of the connector cannot be disengaged as long as the CPA remains in its seated position.
One such CPA is described in U.S. Pat. No. 6,780,045 issued to Shuey et al. on Aug. 24, 2004. Shuey et al. describes a connector position assurance device which can be used in an electrical connector assembly to help ensure that two portions of the electrical connector are fully engaged with each other. The CPA described in Shuey et al. is configured so that the two connector portions cannot be readily disengaged if the CPA is in its fully seated position.
One limitation of the CPA described in Shuey et al. is that it can be dislodged from its fully seated position merely by applying an extraction force to the CPA. Although it contains a protrusion to provide a small amount of resistence to movement from its fully seated position, the protrusion is specifically configured with a sloped surface which allows the CPA to be readily disengaged from the connector. Thus, it may be possible for the CPA described in Shuey et al. to become unintentionally disengaged from the electrical connector, while the connector is in service.
Disengagement of a CPA while the connector is in service may be particularly problematic in certain applications where the electrical connector is subjected to relatively large forces. For example, in the case of a vehicle airbag, the electrical connection at the airbag initiator may encounter large forces when the airbag deploys. Moreover, some airbags are configured for a two-stage deployment such that the electrical connection at the airbag initiator must be maintained after the first stage of deployment, to ensure that the second stage will not be inhibited.
Although it is clear that the electrical connector at an airbag initiator must itself remain engaged to ensure proper initiation of the airbag, it may also be necessary for the CPA to remain in its seated position for the initiator to properly function. This is because airbag initiators may be configured with a service safety feature which does not allow the initiator to function unless the electrical connector is fully engaged and the CPA is fully seated. A built-in short circuit may be configured into the electrical circuit of the airbag initiator, such that the short circuit is opened only when the CPA is in its fully seated position. Thus, even a small amount of movement of the CPA out of its fully seated position will allow the short circuit to close, thereby disabling the initiator. Therefore, in airbag initiators which include this type of built-in short circuit safety feature, and are also configured to deploy an airbag in two stages, it is particularly important that the CPA remain seated after the first stage of deployment to ensure that the airbag will properly deploy during the second stage.
Accordingly, it would be desirable to have an electrical connector with a connector position assurance device which was not readily unseated from the connector. In particular, it would be desirable to have a CPA which did not readily disengage from the connector merely by applying an extraction force to the CPA.